The U.S. Geological Survey says most in the state are slowing down after a spring when near-record snowpack filled the state's rivers with icy, roiling water.

The high water produced the best season in years for river tour companies and kept rescuers busy at one of Utah's most adventurous areas.

Unlike previous years when snow melted quickly, this year's cool spring and sporadic warm spells stretched out the melting process in much of Utah.

Many rivers around the state are still flowing at above-average heights, drawing out prime conditions for rafters, kayakers and boaters. Tour companies said it's welcome relief from previous drought years.

"To have high water and to have it sustained for this long, it's been a long time," said Vicki Mackay of Colorado River and Trail Expeditions in Salt Lake City. "We're celebrating for sure."

One of the diciest spots, though, has been Cataract Canyon in Canyonlands National Park, not far from where the Green River joins the Colorado before thundering over 28 sets of rapids.

A few weeks ago, flow exceeded 50,000 cubic feet per second in the canyon.

That much water increases the odds of boats flipping and people getting into trouble. In some cases, boats were barreling over 15 foot to 20 foot drops.

"For a while there, we estimated that 50 to 60 percent of the boats that tried to go through ended up upside-down," said Denny Ziemann, chief ranger of Canyonlands.

Park rangers set up a special camp in the canyon for rescue operations.

Over several weeks, crews on jet boats pulled 46 swimmers from the river, recovered three disabled or abandoned boats and dealt with three medical emergencies that required helicopter evacuations, Ziemann said.

Conditions have mellowed a bit. On Friday, flows through Cataract Canyon were at about 34,000 cubic feet per second.

"That's still a lot of water but nowhere near where it was a couple weeks ago," said Mike Hawkins, a USGS hydrologic technician.

He said water flows this year in southeastern Utah hadn't been matched since 1983.

Denise Oblak, co-owner of Canyon Voyages Adventure Co. in Moab, said they run many of their tours farther upstream. A popular section of the Colorado near Moab was flowing at more than 21,000 cubic feet per second, several thousand more than is typical this time of year.

"We're all having a lot of fun," Oblak said. "We haven't had a year like this since 1997."

They've seen an uptick in business with an increase in European visitors taking advantage of the weak dollar and more domestic visitors staying closer to home due to high gas prices, Oblak said.

She said her company hasn't had a single problem with the high water, just plenty of satisfying adventure.

USGS officials say the slowing of Utah's rivers this year happened about 10 days later than normal.

In northern Utah, runoff filled most of the reservoirs, according to the USGS. Southern Utah didn't fare as well, losing much of its snowpack in late April and March.